1. Technical Field
The present invention relates to an ink set and a recording method.
2. Related Art
Ink jet recording methods, which allow the user to record high-definition images with relatively simple equipment, have been rapidly advancing in various fields. In particular, stable production of high-quality recordings has been the focus of various studies.
For example, JP-A-2006-160850 is intended to provide an ink, an ink jet recording method, and a recording advantageous in that with respect to images formed using a two-liquid system, a coloring material does not peel off even when the recorded area is rubbed. The publication discloses a water-soluble ink to be used with a reaction solution containing a reactive component that reacts with the water-soluble ink to make the ink aggregate or gel, along with an ink jet recording method and a recording. The water-soluble ink incorporates water, a water-soluble organic solvent, a pigment, and two or more water-soluble polymers mutually different at least in terms of hydrophilicity. At least one of the polymers has a critical coagulation concentration twice or more that of the other polymer(s) and has film-forming properties.
Recordings formed by applying a reaction solution and an ink composition according to JP-A-2006-160850 to a substrate may have insufficient abrasion resistance. That is, the “critical coagulation concentration” according to this publication is a measure of aggregability at 60 minutes after the mixing of the reaction solution and the polymer and does not represent the reactivity during the reaction period, the time required from the contact of the reaction solution and the ink composition to fixation. Furthermore, the “critical aggregation concentration” correlates little with this reactivity because it depends on factors such as the post-reaction structure and diameter of the particles. It is therefore difficult to ensure a superior level of abrasion resistance by making this “critical coagulation concentration” of one polymer twice or more that of the other(s). Worse yet, such an ink composition, when used with a discharge head for ink jet compositions, can cause the discharge head to clog because the water in the ink composition evaporates making the water-soluble polymer(s) in the ink composition with higher hydrophobicity more soluble or film-forming.